Smoothest DA is my S&W registered magnum but I don't shoot it best because of my old eyes and it's thin half coin front sight.

My old 6" blue Python is among the most accurate as it shoots as well as I can. Largely since my departed dad gave it to me it is the last gun I would part with.

I own 3 other revolvers that also shoot as well as I can. All have long barrels. One is a late 70s K22 with 8 & 3/8" barrel, a 3 screw Ruger .30 Carbine, and a Freedom Arms .454. The latter 2 sport 7.5" barrels.